
/*******************************************************************************
 * Copyright IBM Corp. and others 1991
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 *******************************************************************************/

/**
 * @file
 * @ingroup GC_Structs
 */

#include "j9.h"
#include "j9cfg.h"

#include "VMThreadIterator.hpp"

/**
 * @return the next slot containing an object reference
 * @return NULL if there are no more such slots
 */
j9object_t *
GC_VMThreadIterator::nextSlot()
{
	j9object_t *slotPtr;

	switch(_state) {
	case vmthreaditerator_state_start:
		_state += 1;

	case vmthreaditerator_state_slots:
		slotPtr = _threadSlotIterator.nextSlot();
		if(NULL != slotPtr) {
			return slotPtr;
		}
		_state += 1;
		
	case vmthreaditerator_state_jni_slots:
		slotPtr = _jniSlotIterator.nextSlot();
		if(NULL != slotPtr) {
			return slotPtr;
		}
#if defined(J9VM_INTERP_HOT_CODE_REPLACEMENT)
		_state += 1;
		
	case vmthreaditerator_state_monitor_records:
		slotPtr = _monitorRecordSlotIterator.nextSlot();
		if(NULL != slotPtr) {
			return slotPtr;
		}
#endif
		_state += 1;

	default:
		break;
	}

	return NULL;
}

